Air pump for artificial respiration



July 7, 1953 H. TlETZE,

AIR PUMP FOR ARTIFICIAL RESPIRATION 2 Sheets-Sheet 1 Filed Jan. 12, 1951 IN V EN TOR. Maw

BY W

July 7, 1953 H. TIETZE AIR PUMP FOR ARTIFICIAL RESPIRATION Filed Jan. 12, 1951 2 Sheets-Sheet 2 INVHVTOR.

Patented July 7, 1953 Hermann" L'Iietze, [.Lubeck, Germany, assignor -to Ottoj Heinrich Drager, Lubeck,LGermany .epnicati 1-951; Serial 205538 J n, ficrmanyF i 13971950 4 The present invention relates to-=an air pump for the use in an apparatus for artificiaIres-pira tion. I Apparatuses for artificial respiration' are'know in which an air pump produces alternatingly' positive and negative pressure inithe rhythm ofshuman respiration, such as the so-calledviron-lung. In devices of that sort'reciprocating air pumps are used which are driven by means of a crank shaft. Membrane pumps are also known, particularly pumps providedwith animelastic-membrane, which have the advantage that aphysiologically desirable pause between=inhalationaand exhalation can be obtained.

The known devices are-generally provided with a dome which is putoverthe head ofthe'patient while the respiration chamber containing'the patients body is opened. In that event, respiration through the dome replaces the artificial respiration by meansof the respiration chamber of the iron lung, for the time the chamber has-to :be open for attending to thevpatient. The periodic alternations in pressure required for artificial respiration are produced in the dome by the :same air pump. -In changing from onetype'of artificial respiration to the other, the :airpump is switched from the respiration-chamberto the dome. Since the pressure in thedome' isralways opposite to the pressure in the; respiration chamber in which: the patient =is=placed, for instance during inhalation there. is a negative pressurein the chamber, but a'positive pressurelin the dome, respiration isone-hal'f. a cycle out of .phasewhen the air pumpis switched from chamber to the dome, :and the-patient is vexp'osed t'o :an-extended period of exhalation or inhalation, respectively.

;-I'here "are further disadvantages :in the ,use :ofi

the drawbacks of the known air pumps for artifi cial respiration. In the ,present invention one side of the air pump is connected-to the respirationchamber' and the other side of the pump "to the dome. jIngan arrangement. of thattype it possibl t switch ifrom chamber respiration to Qiifilaims. (01. 12830) dome respirationany time-without disturbing the rhythm of respiration of the patient or repeating one period of respiration. "This arrangement-has also the advantage that no complicated switch ing devices are required. t V

In a preferred embodiment of the invention the respiration chamber forms one side of a reciprocating air pump. Preferably the wall of' the respiration chamber is movable and functions as a membrane. In a simple embodiment of the present invention a movable Wallis arranged-in the housing of the apparatus, andtheopening connecting the other sideof theair pu'mpto the atmosphere is preferably disposed in "such manner as to lead to the space enclosedbythe dome when the 'dome'is placed on the apparatus.

In this arrangement the pressure on this side of the pump is equal to the atmospheric pressure aslong as the dome is not used. However, when the dome is connected to the apparatus-positive and negative pressure opposite to the pressure within the respiration chamber is produced within the dome.

The novel features which are considered as characteristic for the'invention are set forth in particular inthe appendedclaims. The invention itself, however, both as to its construction and its method of operatiomtogether with additional objects andadvantages thereof, will be best understood from the following description of specific embodiments when read in connection withthe accompanying drawings, inwhich:

Fig. 1 is a schematic cross-sectional view of an embodiment of the present invention;

Fig; '2 is a schematic cross sectional :view of the air-pump according to a preferred embodiment of the present invention;

- Fig. '3 is a schematic crosssectional viewofthe embodiment shown in Fig. "2-wh'ile respiration is effected in the respiration chamberyand Fig. 4 is a schematic cross-sectional view'o'f the same embodiment while respiration is effected in the dome only.

In the embodiment shownin- Fig. 1-the sides of a double acting air pump [:8 are connected by an air-:duct. l9 to the'respiration chamber I12, and by an air-duct IE to the space enclosed by :the dome -I'l. The-piston 4 is movedto and'froiby acrank .drive 29 rotated by drive mean's,i'not shown. .In' the eventthatthe dome is removed,

the'left sideof theair pump is connectedto the atmosphere, while positive and negative pressure isralternatelyproduced in the respiration chamber J2, whereby artificial respiration of the -,:patientzis caused. V

:In the event; that the dome 5,1 :is secured Jam-the 3 respiration chamber l2, opposed pressure alternations are simultaneously produced in the dome and in the respiration chamber.

In the event that the respiration chamber I2 is opened, and cover 2 is removed, pressure alternations are produced in the dome ll only whereby direct artificial j respiration of the patient is caused.

In a preferred embodiment shown in Figs. 2, 3 and 4, the top of the housing l of the air pump for artificial respiration is closed by an airtightly attached cover 2 provided with openings 3 which can be airtightly closed for attending to the patient H. In the housing I a movable wall 4 is disposed which serves as a membrane of an air pump as used in bellows. The wall is pivotally supported on a shaft 5 on one side, and connected on the other side to the housing by a flexible connection 6, preferably made of a gummed material. The rod 7 passing through an openingii in the bottom plate 9 of the housing 1 is connected to the wall ll, and airtightly separated from the second chamber 14 of the air pump by bellows HP. The patient ll lies in the respiration chamber ii. on mattress 21 which is placed on the air-permeable support 22, said chamber 32 thus forming one side of the air pump, while his head is protruding out of it. Around neck or chest of the patient, a ringshaped sealing device H5 is placed, airtightly sealing the respiration chamber i2 against the atmospheric pressure.

The secondchamber formed by the wall 4 and the bottom plate 9 is connected to the atmosphere by a passage 15 and the opening it. As shown in Fig. 2, the opening it is arranged in such a manner as to be within the area covered by the dome ii, if the dome is placed on the device.

In the arrangement according to Fig. 3, the body of the patient H is exposed to pressure alternations in therespiration chamber l2 whereby artificial respiration is obtained. In the second chamber i i the pressure remains substantially constant since this chamber is connected to the atmosphere by the passage I5 and the opening 16.

In the event that the dome is placed on the device, alternations are produced within the dome which are opposed to the alternations in pressure in chamber 2 (Fig. 2). When cover 2 is taken off, respiration of the patient is only effected through the dome i? (Fig. 4).

It is an advantage of the present invention that switching from chamber respiration to dome respiration is very easy and does not require.any complicated device; Furthermore, the rhythm of respiration remains constant and 'an'exhalation period follows an-inhalation period after switch ing so that the patient does not feel anything of the switch from chambe' respiration to dome respiration.

A further advantage of the present invention is that the physiologically required longer time period of exhalation comparing to inhalation is retained in chamber respiration and dome respiration.

It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of iron lungs differing from the types described above.

While-I have illustrated and described the invention as embodied in an air pump for artificial respiration, I do not intend to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of my invention.

Without further analysis, the foregoing will so fully reveal the gist of my invention that others can by applying current knowledge readily adapt it for various applications without omitting features that, from the standpoint of'prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the following claims.

What I claim as new and desire to secure by Letters Patent is:

,1. An apparatus for artificial respiration, comprising in combination, air pump means having a reciprocating movable member causing compression and expansion of air on opposed sides thereof; drive means driving'said air pump means; a chamber adapted to airtightly enclose the body of a patient substantially one wall of which is formed by one side of said movable member; a dome removably secured to said chamber and adapted to enclose the head of said patient; and air-duct means adapted to connect the other side of said reciprocating movable member to said dome, whereby opposed pressure alternations are produced in said chamber and said dome, respec tively.

2. An apparatus for artificial respiration, comprising in combination, reciprocating air pump means having a reciprocating diaphragm; drive means driving said air pump means; a chamber adapted to airtightly enclose the body of a patient disposed directly adjacent said diaphragm whereby one side of the diaphragm will form a part of the wall of the chamber; a dome removably secured to said chamber and adapted to enclose the head of said patient; and air-duct means her and said dome, respectively.

3. An apparatus for artificial respiration, comprising in combination, a housing; a dome removably secured to said housing and adapted to enclose the head of a patient; a partition dividing said housing into a first chamber and a second chamber, said first chamber being adapted to airtightly enclose the body of said patient and said second chamber provided with an air tight connection leading .to the space enclosed by said dome; a shaft supported in said housing; a reciprocable member pivotally mounted on said shaft and airtightly disposed in said partition and movable from a position reducingthe volume of said first chamber and simultaneously increasing the volume of said second chamber to a position of increasing the volume of said first chamber and simultaneously reducing the volume of said second chamber; and drive means operatively connected to said shaft for moving said reciprocable member to and fro, whereby pressure alternations are produced only in said first chambe!- when said dome is removed, and whereby pressure alternations opposed to each other are produced in said first chamber on one hand and in said second chamber and in said dome on the other hand when said dome is secured to said housing.

4. An apparatus for artificial respiration, comprising in combination, a housing; a dome removablysecured to said housing and adapted to enclose the head or a patient; a partition dividing said housing into' 'a first "chamber and a sec- 7 0nd chamber, said first chamber beingadapted to airtightly enclose the body of said patient and said second chamber provided with an air tight connection leading to the space enclosed by said dome; a removable top on said first chamber; a reciprocable membrane disposed in said partition and being airtightly .connected therein so as to form part of the partition separating said chain ber, said membrane being movable from a position reducing the volume of said first chamber and simultaneously increasing the volume of said second chamber to a position of increasing the volume of said first chamber and simultaneously reducing the volume of said second chamber; and drive means operatively connected with said membrane for moving said membrane to and fro,

of said housing and dome, respectively during movement; and meansfor moving said partition chamber and a-second chamber, said first chamv ber being adapted to airtightly enclose the body whereby pressure alternations are produced only in said first chamber when said dome is removed, and whereby pressure alternations opposed to each other are produced in said first chamber adapted to enclose the body of the patient on one hand and in said second chamber and in said dome adapted to enclose the head of the-patient on the other hand when said dome is secured to said housing, and whereby pressure alternations are produced only in said second chamber and said dome when said dome is secured to said housing, and said first chamber is opened. I

5. An apparatus for-artificial respiration,'com prising in combination, a housing. adapted to airtightly enclose the body, of the patient; adome removably secured to said housing and adapted to enclose the head of said patient and having an air connection with thehousing; an airtight partition wall between said housing and. said dome arranged movably between said housing and of the patient, said second chamber being provided with an airtight connection leading to the space enclosed by the dome; a reciprocable member disposed in said partition, airtightly connected therein and movable from a position'reducing the volume of said first chamber and simultaneously increasing the volume of said second chamber, to aposition increasing the volume of said first chamber and simultaneously reducing the volume of said second chamber; and drive means operatively connected to said movable member' for moving said member toand fro, whereby pressure alternations opposed to each said housing.

dome so'as to reduce and increase the volumes one hand andin said second chamber and dome on the other hand, when said dome is secured to References Cited in the file of this patent UNITED STATESYPATENTS Number Name Date 2,263,844 Hammond Nov.25, 1941 2,427,665

Emerson Sept. 23, 1947 HERMANN TIETZE. 

